Everyone, Booker argued, must pay their "fair share" at a time when the country is facing the enormous burden of paying down debts incurred by two wars.

Booker, who presented the party's 2012 platform, argued Democrats are pursuing an agenda that is not politically divisive, but rather moving the country forward for everyone, regardless of political persuasion.

"It's not about left or right, but moving America forward and our economy forward," Booker said, his remarks interrupted repeatedly by chants of "USA! USA!"

In a dig at Romney and the GOP, Booker said his party's platform was focusing on "big and practical ideas" as opposed to "petty political arguments."

"This is our platform. This is our American mission," Booker declared.

The Newark mayor's remarks came just months after he irritated the Obama campaign by criticizing the president's attacks on Romney's record at Bain Capital. Appearing on NBC's "Meet the Press" in May, Booker called the attacks "nauseating"—a remark that was seized upon by the Romney campaign in its pushback on the Bain attacks.

Until that episode, Booker had been expected to get a higher-profile speaking slot at the DNC. Instead, he was relegated to the 6 p.m. hour. Still, his 12-minute remarks elicited the fieriest reaction from Democratic delegates so far.

As he wrapped up his speech, much of the audience was on its feet, chanting "Cory! Cory! Cory!"